Heart of Scars — Brian P. Easton

The Beast has taken just about everything it can from Sylvester Logan James, and for twenty years he has waged his war with silver bullets and a perfect willingness to die. But fighting monsters poses danger beyond death. 

Sylvester's feud has made him a villainous hero whose only remaining virtue is the greater evil of his adversary. Like a wounded animal, he charges headlong toward his own destruction. He contends with not just the ancient werewolf Peter Stubbe, the cannibalistic demon Windigo, and secret cartels, but with his own newfound fear of damnation. Haunted by cryptic nightmares and insatiable guilt, Sylvester's own resolve will not let him surrender to an easy death. And he may just find that his own demons are his closest allies.